An open hose clamp, in which both end portions of the clamping band have toothed sections for mutual engagement in the overlapping condition, is known from U.S. Pat. No. 4,053,965. To hold the end portions in engagement, it is considered to provide a clip or the like, which is not explained in detail.
U.S. Pat. No. 3,078,532 discloses such a clip which surrounds like a ring both ends of a clamping band which in this case is toothed throughout. Such a ring-shaped clip constitutes an additional structural part, which may be lost and which renders the mounting process more difficult. Moreover, the clip projects from the internal surface of the clamp and is, therefore, problematic with regard to the tightness of the connection.
U.S. Pat. No. 1,804,725 discloses a hose clamp in which one of the toothed sections is provided on the outer side of a tongue, the other on the inner side of a raised portion which has an opening for inserting the tongue in the circumferential direction of the clamp. The raised portion has a web which forms an inner limitation for the inserting opening and lies between the tongue and the hose to be clamped. The web constitutes an unevenness at the inner side of the hose clamp facing the hose and is, therefore, suited for relatively thick and soft hoses only. The web also creates a spacing between the tongue and the hose, which must be overcome when the clamp is tightened.
In the known hose clamp, the tongue is toothed also at its underside so that considerable frictional forces occur upon tightening, which tend to entrain the hose circumferentially. Deformations caused thereby in the hose can lead to leaks between the hose and the underlying object such as a nipple.